DIFFUSIO

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CELL MEMBRANE

Integral Protein

HYDROPHOBIC VERSUS HYDROPHILIC

The heads of the phospholipids are hydrophilic meaning they are attracted to water. The head is made from glycerol and phosphate

The tails are hydrophobic meaning they hate water and want to stay away from it. The tail is made up of two fatty acids

The Hydrophilic heads came together and make a barrier to the water so that the hydrophobic tails don’t have to be in the water.

Hydrophobic is like a phobia which means you are scared of something.

THE FUNCTIONS OF MEMBRANE PROTEINS Hormone Binding Sites~ Binds to specific hormones to change

the behavior of the cell.

Enzyme Action~ On the surface of the cell.

Cell Adhesion~ Enables cells to make tight connections to one another

Cell to Cell communication~ receptors for neurotransmitters at the synapses

Channel Proteins~ allow ions to pass through the membrane

Protein Pumps~ require energy to move ions across the concentration graidents

DIFFUSION

http://www.schooltube.com/video/ef312e55fd344afd96b4/Ch.%207B%20Membranes%20&%20Transport (6:46)

Type of passive transport. Particles move from an area of high concentration to low concentration.

OSMOSIS

Occurs when there is a permeable membrane

Water molecules pass through the cell membrane from low concentration to high concentration

http://www.schooltube.com/video/ef312e55fd344afd96b4/Ch.%207B%20Membranes%20&%20Transport (1:32)

PASSIVE TRANSPORT VIA SIMPLE AND FACILITATED DIFFUSION Simple diffusion does not require energy due to the fact

that it is passive transport.

Ex: Osmosis does not require energy in order to move water across a membrane

Facilitated diffusion requires a specific carrier protein that combine with substances to aid in movement

ACTIVE TRANSPORT

Active transport moves substances like ions or large molecules against a concentration gradient

Use protein pumps and ATP

VESICLES

Used for transport

Carry proteins on the rough ER to the golgi apparatus

Golgi Apparatus prepares the proteins for export from the cell

ENDOCYTOSIS

Bringing in of external substances by the plasma membrane pouching outward~ this forms a vesicle

EXOCYTOSIS

Release of substances from the cell (SECRETION) when a vesicle joins with the plasma membrane